Device for protecting insulators in electric precipitators



A. F. MESTON.

DEVICE FOR PROTECTING INSULATORS IN ELECTRIC PRE CIPITATORS. APPLICATION FILED MAR- 6. 191B.

1 ,332,5 1 0. Patented Mar. 2,1920."

avwemtoz UNITED STATES PATENT curios.

ARCHIBAIID F. MESTON, OF NEW YORK, N. Y., ASSIGNOR T RESEARCH CORPORATION,

' OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

DEVICE FOR PROTECTING INSULATORS TN ELECTRIC PEECIPITATOR'S.

Specification of Letters Patent.

Patented Mar. 2, 1920 I Application-filed March 6, 1918. Serial No. 220,817.

To all whom it may concern:

Be it known that I, ARCHIBALD F. MESTON, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Devices for Protecting Insulators in Electric Precipitators, of which the following is a specification. Y The present invention relates to apparatus for the electrical treatment of gases or gaseous mixtures and more, particularly to devices for protecting the insulators used in such apparatus. i As is well known, electrical precipitators for treating gases 'or, gaseous mixtures for '-trically conductive depositlthereon which inthe purpose of precipitating particles suspended therein comprise electrodes which are charged by a current of high voltage. The insulation presents therefore normally a serious and diflicult problem. This difi'iculty is considerably accentuated in most cases by the particular conditions incident to the treatment of gases containing particles and vapors which, .if allowed to have access to the insulators, gradually form an elec' a relatively short time leads to a break down of the insulation of the system.

. which together with a lower manifold It is the object of the invention .to pro vide a device for efliciently protecting in.

trode and the collecting electrode.

ofielectric treater embodying the invention;

Figs. 2 and 3 are a plan view and 'elevation, respectively of a modification thereof;

Fig. 4 shows another-form of device embodying the principles of the invention and Fig. 5 is a modification the'reof on an en-I' larged scale.

Having reference to Fig. 1, l is a frame 2 and an upper manifold 3 constitutes [a closed casing surrounding thetreater units. This casin may lee-suitably supported asby legs 4. E ech treater'iinit comprises a line or pipe 5 which is the collecting electrode and a thin wire 6 which is the discharge elecsuitably between the electrodes.

trode, The pipes 5 are shown as mounted on cross webs 7 and 8. The discharge electrodes 6 are suspended from a bus bar .9

which is, as usually, supported by insulators 10 on a suitable portion of the casing. At the lower end the wires 6 are held in proper spaced relation bya spacing frame 11 and the usual weights are employed to hold them taut. Openings l3 and 14 in the manifolds admit the gases into and pass them out of the treater.

15 is a bell or hood of electrical conducting material. This bell is symmetrically positioned about the insulator and is electrically connectedwith the bus bar 9'. .One convenient arrangement for the purpose stated is indicated in the drawing where the bell is shown' as clamped between the bus bar 9 and the insulator 10. A disk l6 surrounds the insulator pin adjacent the lower portion thereof. This disk is also of electrical conducting material and electrically connectedwith the frame or any other part of the treater forming part of the electrical rcturn circuit. Disk 16 is in axial alinement with the bell and has substantially the same diameter as the bell, although this is not absolutely essential. The distance between the edge of the bell and the edge of the disk is so chosen that the electric stress is less than that between the discharge eleo- By this arrangement a field of stress is set up which surroundsthe lower part of the insulator like a cylindrical screen. Gas passing through this zone is ionized by'the' electric field and suspended particles are forced out of the gas stream in the well known manner. I V The arrangement 1n Figs. 2 and 3 1s s1m1- lar, but thedisk 20 is placed substantiallyin the plane passing through the edge 17 of the bell 18. The distance between the edge of the bell and the'edge of the disk is again chosen with respect to the distance The device shown in Figs. 2 and disparticularly adapted for the treatment of gas.

containing solid suspended particles. since a considerable quantity of such particles may insulated therefrom by an insulator bushing 32 of porcelain or other suitable material. The bus bar, which is shown of El beam construction is surrounded by a sheet metal tube 33 extending inwardly beyond the bushing 32. A second bushing 3% may be interposed between bushing 32 and tube 33. Cl he interstices between the I beam and the tube 33 maybe filled out by asbestos or other suitable material to prevent flow of gas to the outside.

On the tube 33 is mounted a disk or disks 35. Concentric with these disks is a substantially cylindrical element 36 of electrical conducting material suitably suppbrted on the manifold frame. This cylindrical element 36 has closely spaced perforations 37 substantially opposite the edges of the disks 35. The web 38 carrying the element 36 extends across the entire manifold so that the only communication between the bushing 32 and the treater chamber is through the space defined by the element 36 and the disks 35.

Since the disks 35 are electrically connected with the bus bar 31 and the element 36 with the frame of the collecting electrodes, :1 field of stress is produced therebetween which is similar in all respects to the field in the treater itself. Gas tending to pass through the space between the disks and element 36 is ionized and the particles suspended therein are shot outwardly through the openings 37 and prevented from returning to the gas stream by the imperforate part of the element 36. The precipitated particles may collect below the element 36 and may be from time to time removed.

To limit the electric field more definitely, the portion opposite the disks 35 is curved slightly inwardly. It is obvious that the arrangement may be modified in various ways within the scope of the disclosure.

One such modification is shown in Fig. 5. In this form the cylindrical element 40 consists of two parts 41 and 42 interconnected by a wire screen 43. Rib members 44 may be provided between the parts 41 and 4:2 to rigidly support part all on part 42. The element 40 has an extension 45 connected to the frame ofthe manifold 46. This extension 45 forms a closure to prevent access of the gas to the bushing 32 except through the space between the disks 35 and the element 40. The screen 43 is made to bulge slightly toward the disks While in the foregoing my invention has been described in connection with a precipitator and has particular utility therein, it is obvious that it may be applied to other apparatus and for different purposes.

T claim v 1. The combination with an electric precipitator comprising discharge electrodes, collecting electrodes, a bus bar for supporting the discharge electrodes and an insulator for electrically separating the bus bar from the collecting electrodes, of a substantially cylindrical element surrounding the insulator, of a disk on the bus bar, said cylindrical element and said disk being constructed to define a substantially annular opening leading to the insulator and to produce a field of electric stress thereacross and openings in the wall of the cylindrical element substantially opposite the said disk.

Tn testimony whereof- I affix my si nature.

ARCHIBALD r. MESTON. 

